1. Field of the Invention
The present invention relates to connectors and more particularly, to an electrical connector for receiving two or more cards differing in outer shapes and contact pad positions.
2. Description of the Related Art
Memory cards different in thickness as media for information have been mounted on and connected to information apparatuses through a respective connector exclusive to one particular type of the memory card among the number of the memory cards for reading information stored in the card and storing information into the card. As time goes by, the information apparatuses and hence their boards have been rapidly miniaturized, so that areas occupied by the boards have been limited. What is worse, a plurality of connectors increase the volume of the information apparatuses, which are incompatible with the miniaturization and in no way suitable for portable apparatus. In recent years, the information apparatuses such as portable telephones, telephones, personal digital assistants (PDAs), cameras and the like, various functional expansions are achieved by mounting memory cards such as SIM (subscriber identify module) card, MMC (multimedia card), SD (super density, secure digital) card, memory stick (trademark) and the like, which are incorporated as memories or the like to enhance the convenience while in use. U.S. Pat. No. 6,386,920 issued to Sun on May 14, 2002 discloses a joint socket device for different types of memory cards. The Sun device comprises a lower base and an upper cover being joined to the lower base so as to form a first chamber for containing a SMC, a second chamber for containing a MMC, a third chamber for containing a SD and a forth chamber for containing a MS. The lower base has a conduction part being included in the first chamber, the second chamber, the third chamber and the forth chamber. A plurality of conductive terminals are disposed at the conduction part of the lower base. Each terminal has a contact portion for engaging with a contact pad formed on corresponding SMC, MMC, SD or MS and a solder portion for soldering to a printed circuit board. Hence, the memory cards are electrically connected through the terminals for performing an operation of read or write.
However, in this case, the conduction part of the lower base must be received a large number of terminals for engaging with the contact pads of the four types of memory cards. That is to say, the conduction part must be defined a great many passageways to correspond the terminals. Defining too many passageways is inclined to damnify the plane of the lower base. More, the contact portions of the terminals disposed at the conduction part of the lower base is hardly possible coplanar, so as to result in incomplete interconnection between the terminals of the connector and the contact pads of the memory cards, and in turn, result in incomplete or deficient connection to external equipment. Furthermore, the terminals are arranged and fixed in the lower base in a same direction and parallelly spaced apart one another. Therefore, the solder portions of respective terminals are concentrated to one of rear edge or front edge of the lower base. These solder portions tend to be interfered with each other, thus rendering unsatisfied layout thereof.
Hence, an improved connector for memory cards is needed to overcome the foregoing shortcomings.